MK2 Cortina not idling

[fliptrip]

Hi Everyone

 

I have a 1967 MK2 1500 Cortina.

 

I've had it for a few months and have been driving it every now and then.

Until recently...I took it for a drive on the weekend and pretty much had to use the choke the whole time or else it would run rough - even while doing 80 on the motorway (I would push the choke in and it would start running rough and then I would pull it out it would stop running rough - through all 4 gears)

 

And then when approaching redlights, when I guess the revs got too low it would turn itself off. Turn the key, and off we went again.

 

Until I got home turned it off. And then later in the afternoon when I tried to move it, it wouldn't even idle with the choke out.

 

So I had a quick play with the idle screw but that's about where I am at.

Currently if I wind (in?) the idle screw fully with the choke on it will idle at really high revs but as soon as I push the choke in it dies so being a brain surgeon I'm thinking it has to be something to do with the carby/idle/mixture?

 

NB/FYI I had a check of the distributor and it was a bit loose (could twist it left and right) have since tightened it up and checked the cap and in the underside, next to two of the metal points are explosions in the plastic, the metal bits fully intact and still shiny.

 

Am in West Auckland.

 

Cheers

[AllTorque]

If the distributor was loose you will need to set the ignition timing with a timing light. Sounds like your also not getting enough fuel. Would pay to chuck in a new fuel filter for a start

[AllTorque]

Also, what do you mean "explosions in the plastic"? Is that in the dizzy cap?

It is probably worth giving the car a good tune up with new points, condenser, rotor, cap, leads, plugs.

Set your valve clearances too.

I am assuming some of this stuff may be new to you. If so get a workshop manual, sit down and have a read. Setting points and stuff can be tricky for a beginner but it is part of regular maintenance of an old car, so if you can DIY you'll save yourself $$ and diagnose problems when it stops on the side of the road at night in the rain.

[fliptrip]

Thanks for the reply. Fuel flows fine from the pump, and between the tank and pump there is a filter which I could replace just for the sake of it.

 

You sir, are correct, I have never done ignition/electrical before - In the future was thinking converting to electronic dizzy would be the way to go?

 

But for the meantime I'll do as you say regarding the timing, points etc. Regarding not getting enough fuel - would this be both the idle screw & fuel mixture?

 

And yeah, the distributor cap - next to two of the metal bits is where it has been sparking and has eroded some of the plastic, metal bits are still perfect. Just weird as if the loose dizzy was causing that you would think there would be "explosions/pitted" next to all 4 metal points?

 

Cheers

[AllTorque]

Lack of fuel / running lean could be caused by a few things. If you screw the mixture screw in it makes it lean, screw it out makes it rich (at idle). If you can get a vacuum gauge it will make it easier to set the idle mixture. Start a bit rich then screw it in until the gauge needle just starts to drop from max vacuum, then screw out 1 quarter turn.

This only sets the idle mixture. Sounds like you are running lean constantly if you need to use the choke. This could be caused by a bit of dirt in the carb. Best bet is to take the top of the cab off and blow out all the passages with compressed air.

[fliptrip]

Thanks for the advice so far, inspected the plugs and they were all sooty, but would almost expect that from running it on the choke?

Took the carb off and gave it a quick clean out. Put it back on, started fine, and kept idling, at good low revs even without the choke on, putting the choke in would almost cause it to stall?) ,so had enough courage to took it for a quick drive, started out fine, first intersection, off the gas, idled perfectly, next intersection, idled fine off the revs again, next intersection (hill) stalled and then from then on was sluggish driving even with the revs. So am very inclined to say it's carb related.

Will take the carb off and into someone with some experience.

 

The plot thickens..

[crispymk2]

Carby float bowl might be cactus?

[fliptrip]

Took the carb apart and had an expert look at it - from his observation everything in pretty good nick and how it should be - Made a small adjustment to how the float sits - when it was fully down, it would let the needle fall too far and so it the needle was on an angle making it difficult for the float to push it back up as it wasn't vertical. So adjusted this so the float didn't open as fully.

 

The cone on top of the little brass pin which the float moves up and down has a slight worn ring which if anything should allow more fuel through?

 

Gave it a good clean out but nothing seemed blocked.

 

About to fit it so will let you know.

 

Have fitted it and can now get it to idle on the choke pretty well, and once warm (couple minutes) push in the choke and still idles and then once you pull the choke out, it runs rougher.

 

Will let it cool down and then start it up again to see if the results are the same - and then take it for another test drive, and hope the same doesn't happen as last time!